日前, IPC发布今年8月的北美PCB业统计数据.数据显示刚性PCB在8月份的订单出货比上升到1.06,但出货量及订单量同比2006年8月分辨下降了10.1和5.1个百分点.柔性PCB的订单出货比8月份达到1.07,同比2006年八月的出货量和订单量则下降了24.7及10.0个百分点.具体数据如下. PCB Industry Growth Rates and Book-to-Bill Ratios Announced Rigid PCB shipments are down 10.1 percent and bookings are down 5.1 percent in August 2007 from August 2006. Year to date, rigid PCB shipments are down 10.4 percent and bookings are down 13.4 percent. Compared to the previous month, rigid PCB shipments increased 9.8 percent and rigid bookings increased 12.8 percent. The book-to-bill ratio for the North American rigid PCB industry in August 2007 climbed to 1.06. Flexible circuit shipments in August 2007 were down 24.7 percent and bookings were down 10.0 percent compared to August 2006. Year to date, flexible circuit shipments are down 5.4 percent and bookings are up 6.3 percent. Compared to the previous month, flexible circuit shipments increased 0.4 percent and flex bookings were up 17.7 percent. The North American flexible circuit book-to-bill ratio rose to 1.07 in August. For rigid PCBs and flexible circuits combined, industry shipments in August 2007 decreased 11.1 percent from August 2006, and orders booked decreased 5.4 percent from August 2006. Year to date, combined industry shipments are down 10.1 percent and bookings are down 12.3 percent. Compared to the previous month, combined industry shipments for August 2007 are up 9.2 percent and bookings are up 13.1 percent. The combined (rigid and flex) industry book-to-bill ratio in August 2007 grew to 1.06. While the industry is still around 10 percent below last years sales levels, it is holding steady, said IPC President Denny McGuirk. Bookings looked especially strong in August, which indicates the potential for strong sales over the next quarter, he added. The book-to-bill ratios are calculated by dividing the value of orders booked over the past three months by the value of sales billed during the same period from companies in IPCs survey sample. A ratio of more than 1.00 suggests that current demand is ahead of supply, which is a positive indicator for sales growth over the next two to three months. Book-to-bill ratios and growth rates for rigid PCBs and flexible circuits combined are heavily affected by the rigid PCB segment. Rigid PCBs represent an estimated 88 percent of the current PCB market in North America, according to IPCs World PCB Production and Laminate Market Report for the Year 2006. The Role of Domestic Production  IPCs monthly survey of the North American PCB industry tracks bookings and shipments from U.S. and Canadian facilities, which provide indicators of regional demand. These numbers do not measure U.S. and Canadian PCB production.To track regional production trends, however, IPC asks survey participants for the percent of their reported shipments that were produced domestically (i.e., in the USA or Canada). In August 2007, 87 percent of total PCB shipments reported were domestically produced. Domestic production accounted for 86 percent of rigid PCB and 97 percent of flexible circuit shipments in August by IPCs survey participants. These numbers are significantly affected by the mix of companies in IPCs survey sample, which remains constant throughout each calendar year, but may change with the January survey results.Bare Circuits Versus Assembly Flexible circuit sales typically include value-added services such as assembly, in addition to the bare flex circuits. In August, the flexible circuit manufacturers in IPCs survey sample indicated that bare circuits accounted for about 84 percent of their shipment value reported for the month. Assembly and other services make up a large and growing segment of flexible circuit producers business. This figure is also sensitive to changes in the survey sample, which may occur at the beginning of each calendar year. Interpreting the Data Year-on-year and year-to-date growth rates provide the most meaningful view of industry growth. Month-to-month comparisons should be made with caution as they may reflect cyclical effects. Because bookings tend to be more volatile than shipments, changes in the book-to-bill ratios from month to month may not be significant unless a trend of three consecutive months or more is apparent. It is also important to consider changes in bookings and shipments to understand what is driving changes in the book-to-bill ratio. The information in IPCs monthly PCB industry statistics is based on data provided by a representative sample of both rigid and flexible PCB manufacturers in the USA and Canada. IPC publishes the PCB Book-to-Bill Ratio and the Interconnect Manufacturing Services (IMS) Business Report each month. Statistics for the previous month are not available until the last week of the following month.